Piezoelectric gas lighter



'FebQiO, 1970 I TAKESHIYINAGARI I 3,494,710

PIEZOELECTRIC GAS LIGHTER Filed Dec. 18, 1 967 4 Sheets-Sheet 1 Feb;.10, 1970 TAKESHI INAGAKI 9 0 PIEZOELECTRIC GAS LIGHTER Filed Dec. 18,1967 4 Sheets-Sheet B Feb.1b; 1970"- PIEZOELECTRIC GAS LIGHTER Filed Dec. is, 1967 4 Sheets-Sheet a TYAKESHI l lfl AG AKl I 3,494,710v A I Feb.10, 1970 ITAKESHI INAGAKI 3,494,710

PIEZOELECIRIC GAS LIGHTER Filed'Dec. 18 1967 4 Sheets-Sheet 4 UnitedStates Patent 3,494,710 PIEZOELECTRIC GAS LIGHTER Takeshi Inagaki, 16Senjunakai-cho, Adachi-ku, Tokyo, Japan Filed Dec. 18, 1967, Ser. No.691,530 Claims priority, application Japan, Feb. 24, 1967, 42/15,493;June 17, 1967, 42/38,722 Int. C]. 13231 2/00 U.S. Cl. 431-143 ClaimsABSTRACT OF THE DISCLOSURE This invention relates to a liquefied gaslighter and more particularly to a piezoelectric gas lighter in which agaseous fuel is ignited by a spark produced from a piezoelectric elementcontained therein.

Lately, various kinds of piezoelectric gas lighters which have apiezoelectric ignition system as a substitute for a flint and sparkingwheel have been proposed. In view of the fact that the piezoelectricelement can avoid the trouble of replacing a flint and has asemi-permanent life, the piezoelectric gas lighters are muchappreciated. In practice, however, it is diflicult to apply apiezoelectric ignition system to a compact gas lighter of pocket typeand, therefore, most of the piezoelectric gas lighters which haveheretofore been marketed are of large type, such as table lighter.

The piezoelectric elements produced nowadays have, in general, a highenergy conversion efficiency; for example, a voltage of 15-20 kilovoltscan be generated from a piezoelectric element which is fabricated from alead zirconate-lead titanate polycrystal and has a size of 3.5 mm.diameter x mm. length. However, the voltage developed is proportional tothe pressure applied, and such high voltage is generated only whensuflicient pressure is applied to the piezoelectric element. Therefore,even with any existing excellent piezoelectric element, it is impossibleto generate a voltage required for igniting the gaseous fuel without asuitable mechanical means operative for producing a suflicient pressure.Such mechanical means generally needs a relatively large construction,so it has been difiicult to be contained in a compact gas lighter. It isthe very reason why it has heretofore been diificult to produce a pockettype piezoelectric gas lighter.

It is therefore one object of the present invention to provide a pockettype piezoelectric gas lighter which is as small as orsmaller thanconventional flint gas lighters of pocket type.

Another object of the present invention is to provide a lighter of thekind described which can be easily disassembled and reassembled.

A further object of the invention is to provide a lighter of the typestated which can effect ignition of the gaseous fuel by a single actionperformed by the user without fail.

Another object is to provide a piezoelectric gas lighter of thecharacter stated which is light in weight and durable.

s A still further object of the invention is to provide a lighter of thecharacter described which is simple in construction and which can bemanufactured and sold at a reasonable cost.

Further objects, features and advantages of the invention will becomeapparent from the following detailed description and annexed drawings inwhich:

FIGURE 1 is a perspective view of a lighter embodying the presentinvention;

FIGURE 2 is an enlarged vertical sectional view of the lighter shown inFIG. 1, with a fingerpiece, illustrating the internal structure thereof;

FIGURE 3 is an enlarged perspective view of a casing unit of the lighterconsisting of a casing and the fingerpiece;

FIGURE 4 is an enlarged perspective view showing a fuel reservoir unitand an ignition unit of the lighter shown in FIG. 2;

FIGURE 5 is an enlarged cross-sectional view illustrating an actuatingmechanism in association with the fingerpiece;

FIGURE 6 is a cross-sectional view taken along the line VI-VI of FIG. 5;

FIGURE 7 is an enlarged exploded view of a fingerpiece supporting unit;and

FIGURE 8 is an enlarged exploded View of the ignition unit.

In FIGURES 1 to 8, like portions or parts are designated with likenumerals.

Referring to FIGURES 1 to 3, one embodiment of the present invention isillustrated as applied to a pocket type liquefied gas lighter 10 havinga casing 11 of a rectangular shape. The casing 11 is provided at one endof its top with an opening 12 for discharging a flame from a burner.FIG. 2 illustrates the state in which a fuel reservoir unit 1311 and aignition unit 14a shown in FIG. 4 are encased by a casing unit shown inFIG. 3. To the lower opening of the fuel reservoir 13 is fixed aconcave-shaped base plate 15 which functions as a common bottom wallboth for the reservoir and the casing 11. The reservoir .13 is providedat its upper portion with a burner valve 17 having a burner nozzle 16and an adjusting wheel 18 for regulating the height of flame from theburner nozzle, and also at the bottom portion with a filling valve 19.On a portion 20 of the bottom plate or the bottom wall 15, adjacent tothe reservoir, is mounted the ignition unit 14a by means of a screw 22which is adapted to engage a tapped hole 21.

As shown in FIG. 4, the ignition unit 14a consists essentially of apiezoelectric element 23, a hammer 24, a coil spring 25, a support 26and a slidable member 27 which are all disposed within an invertedU-shaped frame 14 in the manner depicted. The hammer 24 is resilientlymovably supported by the coil spring 25 axially pierced by the support26 and is adapted to strike against the piezoelectric element 23 by theaction of said spring. The hammer 24 has a vertical bore 24' which opensat its lower end and vertically slidably engages with the upper portionof the support 26 so that the hammer may be vertically guided by thesupport during its movement. The slidable member 27 is at its cut-outportion 48 in releasable engagement with a lateral pin 28 projectingrearwardly from the hammer 24. The fuel reservoir 13 has at its sidewall a U-shaped connecting lug 29, to which the frame 14 is connected bymeans of a screw 30, thereby enabling the ignition unit or ignitingmechanism assembly 1411 to be securely mounted on the bottom plate 15 incooperation with the screw 22.

When the ignition unit 14a, which is mounted on the bottom plate 15together with the fuel reservoir unit 13a, is inserted, as shown in FIG.2, into the casing unit 11:: through from the lower opening thereof, theslidable member 27 is brought, at its tongue-like lug 31, intoengagement with a pair of rectangular projections 33, 33 which extendfrom a fingerpiece 32 provided on the rear wall of the casing 11.Accordingly, when the fingerpiece is depressed, the hammer 24 is forcedto be lowered to compress the coil spring 25 for energization.

Referring now to FIGURES to 7, the fingerpiece 32 of triangularcross-section is so attached to the casing 11 as to cover a verticallyelongated opening 34 formed in the rear wall of the casing. Therectangular projections 33, 33 project from a U-shaped intermediatemember 35 having legs 35a, 35b which are inserted respectively into apair of horizontal slits 36a, 36b of a resilient slide 36, said legsprojecting rearwardly out of the opening 34 of the casing 11 andpressing said slide 36 against the inner face of the side wall of thecasing. The projecting legs 35a, 3512 are inserted into a pair of slits37a, 37b of a base plate 37 of the fingerpiece. The U-shaped member 35,the slide 36 and the base plate 37 are fastened together by means of ascrew 38. Thus, the fingerpiece 32 is vertically movably attached to therear side of the casing by means of a screw 39 which is in threadedengagement with the U-shaped member 35. A a result, the fingerpiece 32and the U-shaped member 35 can be vertically moved between the upper andlower limits of the opening 34.

The slidable member 27 has at its upper portion a pair of ears 27a, 27bwhich are inserted respectively into a pair of vertical guide slits 43,43' formed in upper portions 14'a 14b of the side walls 14', 14" of theframe 14 that protrude rearwardly, so that the slidable member 27 canslide vertically along said slits. The slidable member 27 is upwardlyurged by means of a coil spring 45 the lower end of which is connectedto the slidable member at 46, and the upper end of which to a shaft 44which traverses the side walls 14, 14" of the frame 14. To the shaft 44is secured a base portion of a wire spring 47, of which the tip portion47' bears against the intermediate portion of the slidable member 27 sothat a roller 42, which is rotatably attached to the leg portions 40,40' of the slidable member 27 by means of a pivot pin 41, may be broughtinto slidable contact with guide edges 14c, 14d of the frame 14.

Referring now to FIG. 8, the ignition unit previously shown in FIG. 4 isdismounted and illustrated by parts, which can be readil reassembled inaccordance with the manner as will be hereinafter described.

The side walls 14, 14" of the frame 14, which are connected by an upperwall 14e integrally formed therewith, have at their lower portions thevertical guide edges 14c, 14d for the roller 42 that leads to sled-likecurved edges 1411, 141. The piezoelectric element 23 packed in asuitable plastic mold has its lower end 23' exposed downwardly.

A supporting plate 49 has in its central portion a circular aperture 50in which is inserted the lower end 23' of the piezoelectric element '23.The supporting plate 49 is secured to the frame 14 by inserting a pairof ear portions 49a, 49b of the plate in a pair of slits 51 of theframe, respectively so as to secure the element 23. The slidable member27, coil spring 45 and wire spring 47 are disposed within to the frame14 in the manner described in connection with FIGURES 5 and 6.

The support 26 receives at its boss portion 26 a lower supporting plate52 which is fastened together with a washer 53 by means of a nut 54adapted to engage a thrreaded portion 26" of the support 26. On thesupport 26 is axially mounted a coil spring 25, which rests at its lowerend on the supporting plate 52 and bears at its upper end against thehammer 24. The supporting plate 52 is secured to the frame 14 byinserting a pair of ear portions 52a, 52b thereof in a pair of slits52', 52" of the frame. Subsequently, the side walls 14', 14" of theframe are fastened by means of a screw 55 which passes through a pair ofholes 54, 54' thereof. To the lower end of the frame 14 is attached aconcave-shaped bottom member 56, through the medium of which the frame14 is attached to the bottom plate of the fuel reservoir 13 at by meansof a screw 22 screwed into a tapped hole 57 of the boss portion 57 ofthe support 26 through a hole 21 of the bottom plate and a hole 56 ofthe bottom member.

A valve opening lever 58 has a forked end portion 58' and a pair of tailportions or legs 58a, 58b and is pivotally mounted at its legs on theupper portions of the walls of the frame 14 by means of pivots 60passing through holes 59 of the legs and holes 59 of the frame,respectively so that the curved end portions of the legs 58a, 58b mayobliquely downwardly extend across the vertical guide slits 43, 43. Thelever 58 is, as shown in FIG. 2, at its forked portion 58, in engagementwith a neck portion 16' of the burner nozzle 16.

Indicated by numeral 61 is electrode, the base portion 61b of which issecured to the frame 14 at 61b by means of a screw 62, and the end point610 of which projects laterally, as clearly shown in FIG. 2, just abovethe burner nozzle 23 so as to be located opposite to the other electrode23a extending from the piezoelectric element 23, forming a spark gap.Between a top portion Me of the ignition unit and an upper wall of thecasing 11 is disposed a suitable cushion 63 so as to absorb the impactagainst the casing that is produced when the hammer strikes against thepiezoelectric element. When the assembly of the ignition unit and thereservoir unit 13a is inserted in the casing through the lower, openingthereof, an adjusting wheel 18 with its edge milled is inserted in anopening 64 of the casing, and attached, at its internally fluted bore18a, to a burner nozzle 16. Thereupon, the assembly of the two units14a, 13a is inserted further in thecasing till the upper edge 1501 ofthe upstanding peripheral wall of the bottom plate 15 fits the edge ofthe lower opening 11' of the casing 11. Then, the screw 65 is screwedinto a tapped hole 67 formed in a tongue-like portion 56a of the bottommember 56 of the frame 14, through an aperture 66 of the casing 11.Thus, the assembling operation of the piezoelectric gas lighter, whichcomprises the casing unit 11a, the reservoir unit 13a and the ignitionunit 14a is completed.

In operation, when the fingerpiece 32 is manually depressed by pressingan upper surface 32a thereof, the slidable member 27 is depressedagainst the action of the spring 45 and, at the same time, the hammer 24having a lateral pin 28, which is in releasable engagement with acut-out portion 48 of the member 27, is lowered by said membercompressing the coil spring 25. Also, when the slidable member islowered, its ears 27a, 27b are adapted to slide down along the guideslits 43, 43 of the frame and to press down the curved legs 58a, 58b ofthe valve opening lever 59, causing the forked portion 58' of the leverto be raised. As a result, the burner valve 17 is opened, and the fuelin the reservoir 13 is discharged through the nozzle 16.

As the slidable member 27 is further lowered along the guide edges 14c,14d of the frame 14, its lower end is forced to mount the sled-likecurved end portions 14h, 14i with its roller 42, thereby causing the pin28 of the hammer 24 to be released from the engagement with the cut-outportion 48 of the slidable member 27. The moment the pin is released,the hammer is caused to spring up by the action of the coil spring 25energized and strikes against the lower end 23 of the piezoelectricelement 23 to thereby produce a spark at the spark gap between theelectrodes 23a, 61a, causing the gas flowing out of the burner nozzle 16to be ignited. The flame thus produced is discharged through an opening12 of the casing 11.

On releasing the pressure applied to the fingerpiece 32, the slidablemember is returned to its normal position together with the fingerpieceby the action of the spring 45. In the normal position, the slidablemember is brought, at its cut-out portion 48, into engagement withthepin 28 of the hammer again. At the same time, the legs 58a, 58b ofthe valve opening lever 58 are released from the pressure exerted by theears 27a, 27b and the forked portion of the lever is returned to itsoriginal position, thereby causing the burner valve 17 to beautomatically closed.

As may be seen from the foregoing, the piezoelectric liquefied gaslighter according to the present invention is fabricated-by threesimplified units, the casing unit 11a, the fuel reservoir unit 13a andthe ignition unit 14, and accordingly, it can be readily dismounted andreassembled. Consequently, when there is some trouble with the lighter,the defective unit or part thereof can be readily repaired.

What-is claimed is:

1. A dismountable piezoelectric liquefied gas fueled lighter comprisinga casing unit and an assembly composed of 'a fuel reservoir unit and anignition mechanism unit saidassembly being removably mounted in saidcasing unit," said ignition mechanism unit .being detachably connectedto said fuel reservoir unit in a side-by-side relationship therewith,said casing unit including a casing, having a; lower opening throughwhich said assembly is removably mounted in the casing, and manuallyoperable actuating means vertically movably mounted on said casing,said; fuel reservoir unit including a fuel reservoir, having a bottomwall common to said casing and adapted to closthe lower opening thereofa burner-valve assembly and a filling valve assembly, the two saidassemblies being fixed to the top and the bottom wall of said reservoir,respectively, said ignition mechanism unit including a verticallyelongated U-shaped frame, said frame having side walls formed withsloping cam surfaces at the lower portions ithereof, a piezoelectricelement removably secured to; an upper portion of said frametherewithin, a pair off'electrodes in circuit with said piezoelectricelement and set so as to provide a spark gap above the burner of saidburner-valve assembly and impacting means operatively connected withsaid manually operable actuating means, said impacting means includinghammer means having a vertical bore opening at its lower surface, andbeing vertically reciprocably disposed underneath said piezoelectricelement within said frame by means of a stationary vertical guide postextending into the vertical bore of; said hammer means, said impactingmeans also including coil spring means mounted concentrically with saidguide post in said frame and abutting at its upper end against theunderside of said hammer means to normally bias said hammer meansupwardly toward said piezoelectric element and means vertically slidablyfixed to said frame and arranged so as to be engageable with said hammermeans to lower the latter along said vertical guide post in associationwith said manually operable actuating means, to compress said coilspring means for energization thereof, said slidable means being adaptedto release said hammer means when brought into contact with thesloping-cam surfaces of said frame to permit said hammer means to bedriven by said coil spring means to thereby impart an impact to saidpiezoelectric element to cause a spark, across said spark gap forignition of fuel, said ignition mechanism unit also having a valveopening lever pivotally fixed to said frame and operatively connected tosaid manually operable actuating means so that fuel is supplied to saidburner synchronously with operation of said manually operable actuatingmeans.

2. A dismountable piezoelectric liquefied gas fueled lighter as claimedin claim 1, wherein said hammer means includes a laterally rearwardlyprojecting pin adapted to be engaged by a cut-out portion formed at thelower portion of said slidable means, said slidable means being normallyurged to contact the rear edges of the side walls of said U-shaped frameby spring means and having at its upper portion a pair of cars laterallyextending in opposite directions and slidably engaged in vertical guideslits formed in the side walls of said frame, and also having at itslower end roller means adapted to roll on the rear edges of said sidewalls for facilitating sliding movement of said slidable means on saidrear edges and also for facilitating releasing of engagement betweensaid hammer means and said slidable means.

3. A dismountable piezoelectric liquefied gas fueled lighter as claimedin claim 1, wherein said ignition mechanism unit is connected to saidfuel reservoir unit in such a way that the side walls of said U-shapedframe are removably secured to a bracket, provided on a side wall ofsaid fuel reservoir, by screw means, and the bottom of said frame isremovably secured to the bottom wall of said reservoir by screw means.

4. A dismountable piezoelectric liquefied gas fueled lighter as claimedin claim 1, wherein said casing is of a rectangular shape and has in itsupper wall an outlet opening for discharging a flame and in its rearwall a vertically elongated aperture along which said manually operableactuating means is adapted to slide, said actuating means being of asubstantially triangular shape in side view and mounted on the outerside of the rear wall of said casing.

5. A dismountable piezoelectric liquefied gas fueled lighter as claimedin claim 1, wherein said valve opening lever is provided with a forkedend portion engaging the burner of said burner-valve assembly and alsowith a pair of curved legs extending rearwardly and obliquely downwardlyand adapted to be engaged by a portion of said slidable means to therebyopen the valve of said burnervalve assembly.

References Cited UNITED STATES PATENTS 3,200,295 8/1965 Owens et al431-131 3,295,024 12/1966 Newman 431-132 X 3,387,912 6/1968 Goto 431-3,425,783 2/ 1969 Goto 431-255 EDWARD J. MICHAEL, Primary Examiner US.Cl. X.R. 431-255

